Sesterterpenes and phenolic alkenes from the Thai sponge Hyrtios erectus

Abstract Sesterterpene, erectusolide A ( 1 ), six phenolic alkenes, erectuseneols A−F ( 2 – 7 ) and nine known compounds, luffalactone ( 8 ), luffariolide E ( 9 ), (6 E )- and (6 Z )-neomanoalide 24,25-diacetates ( 10 and 11 ), 6,6-dimethylundecane-2,5,10-trione ( 12 ), threo - and erythro -cavernosines ( 13 and 14 ), (4 E ,6 E )-dehydromanoalide ( 15 ), echinoclerodane A ( 16 ), were isolated from the marine sponge Hyrtios erectus . Compound 13 was isolated for the first time from a natural source. The structures of these compounds were elucidated on the basis of spectroscopic analysis. The phenolic alkenes 3 and 7 , the sesterterpenes 8 – 11 and 15 , and compounds 12 – 14 were evaluated for cytotoxic activities against six cancer cell lines, MOLT-3, HepG2, HeLa, HuCCA-1, A549, and MDA-MB-231.